Recently, studies have been conducted to use a light-emitting element such as an organic electro-luminescent element as a light source for lighting apparatuses. One of the characteristics required of the lighting apparatuses is the emission of white light. For example, Patent Document 1 describes that, as shown in FIG. 1, regions 520 emitting red light, regions 530 emitting green light, and regions 540 emitting blue light are formed on a single substrate, and the regions are made to emit light at the same time, whereby white light is emitted.
Patent Document 2 describes a lighting apparatus including multiple panel-shaped organic light-emitting sources.
In addition, Patent Documents 3 and 4 describe the lamination of multiple organic EL light-emitting layers between an anode and a cathode. These documents describe that a charge-generating layer is provided between each of the multiple organic EL light-emitting layers.